<!DOCTYPE html><html lang="[&quot;zh-Hans&quot;,&quot;zh-CN&quot;,&quot;default&quot;]"><head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1"><meta name="description" content="Peer-to-Peer笔记"><meta name="keywords" content="P2P"><meta name="author" content="wenmu"><meta name="copyright" content="wenmu"><title>Peer-to-Peer笔记 | 温木的博客</title><link rel="shortcut icon" href="/melody-favicon.ico"><link rel="stylesheet" href="/css/index.css?version=1.6.1"><link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/font-awesome@latest/css/font-awesome.min.css?version=1.6.1"><link rel="dns-prefetch" href="https://cdn.staticfile.org"><link rel="dns-prefetch" href="https://cdn.bootcss.com"><link rel="dns-prefetch" href="https://creativecommons.org"><link rel="dns-prefetch" href="http://ta.qq.com"><script>(function() {
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} </script><meta name="generator" content="Hexo 4.2.0"></head><body><i class="fa fa-arrow-right" id="toggle-sidebar" aria-hidden="true"></i><div id="sidebar"><div class="toggle-sidebar-info text-center"><span data-toggle="切换文章详情">切换站点概览</span><hr></div><div class="sidebar-toc"><div class="sidebar-toc__title">目录</div><div class="sidebar-toc__progress"><span class="progress-notice">你已经读了</span><span class="progress-num">0</span><span class="progress-percentage">%</span><div class="sidebar-toc__progress-bar"></div></div><div class="sidebar-toc__content"><ol class="toc"><li class="toc-item toc-level-3"><a class="toc-link" href="#什么是-NAT"><span class="toc-number">1.</span> <span class="toc-text">什么是 NAT</span></a></li><li class="toc-item toc-level-3"><a class="toc-link" href="#NAT-的分类"><span class="toc-number">2.</span> <span class="toc-text">NAT 的分类</span></a></li><li class="toc-item toc-level-3"><a class="toc-link" href="#对称-NAT"><span class="toc-number">3.</span> <span class="toc-text">对称 NAT</span></a></li><li class="toc-item toc-level-3"><a class="toc-link" href="#完全锥形-NAT"><span class="toc-number">4.</span> <span class="toc-text">完全锥形 NAT</span></a></li><li class="toc-item toc-level-3"><a class="toc-link" href="#判断顺序"><span class="toc-number">5.</span> <span class="toc-text">判断顺序</span></a></li></ol></div></div><div class="author-info hide"><div class="author-info__avatar text-center"><img src="https://i.loli.net/2020/02/27/xwaBoOj158MfNyq.jpg"></div><div class="author-info__name text-center">wenmu</div><div class="author-info__description text-center">记录一些在工作中或学习新知识时学到的一些知识点；正所谓好记性不如一个烂笔头，温故而知新！</div><hr><div class="author-info-articles"><a class="author-info-articles__archives article-meta" href="/archives"><span class="pull-left">文章</span><span class="pull-right">115</span></a><a class="author-info-articles__tags article-meta" href="/tags"><span class="pull-left">标签</span><span class="pull-right">52</span></a><a class="author-info-articles__categories article-meta" href="/categories"><span class="pull-left">分类</span><span class="pull-right">30</span></a></div></div></div><div id="content-outer"><div class="no-bg" id="top-container"><div id="page-header"><span class="pull-left"> <a id="site-name" href="/">温木的博客</a></span><i class="fa fa-bars toggle-menu pull-right" aria-hidden="true"></i><span class="pull-right menus"><a class="site-page" href="/">首页</a><a class="site-page" href="/archives">文章</a><a class="site-page" href="/tags">标签</a><a class="site-page" href="/categories">分类</a></span></div><div id="post-info"><div id="post-title">Peer-to-Peer笔记</div><div id="post-meta"><time class="post-meta__date"><i class="fa fa-calendar" aria-hidden="true"></i> 2020-01-09</time><span class="post-meta__separator">|</span><i class="fa fa-inbox post-meta__icon" aria-hidden="true"></i><a class="post-meta__categories" href="/categories/P2P/">P2P</a></div></div></div><div class="layout" id="content-inner"><article id="post"><div class="article-container" id="post-content"><h3 id="什么是-NAT"><a href="#什么是-NAT" class="headerlink" title="什么是 NAT"></a>什么是 NAT</h3><p>NAT（Network Address Translation，网络地址转换），简单说，就是把局域网中的机器和外部进行通信时，映射公网 IP 和端口的过程。<br>比如你在局域网中的地址是 192.168.1.100，你的公网地址是 119.125.123.12，当你和异地的朋友通信时，你发出的信息是通过你的公网地址发出去的，为了区分是局域网中的哪个机器，通常会分配一个端口，比如你发出的信息时，给你分配的公网地址和端口是：119.125.123.12:8223，那么当互联网上的任何人往上面地址发送信息，都会发到你机器上（前提是没设置通信限制，下面有讲解，这里说的是完全锥形 NAT）</p>
<a id="more"></a>

<h3 id="NAT-的分类"><a href="#NAT-的分类" class="headerlink" title="NAT 的分类"></a>NAT 的分类</h3><p><img src="https://upload-images.jianshu.io/upload_images/1348523-3743e41de25d9991.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240" alt="image.png"></p>
<p>电信级的网关都是“对称 NAT”，比如移动、连通、电信</p>
<h3 id="对称-NAT"><a href="#对称-NAT" class="headerlink" title="对称 NAT"></a>对称 NAT</h3><p><img src="https://upload-images.jianshu.io/upload_images/1348523-d1680bcfd70082ca.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240" alt="image.png"></p>
<p>简单说就是客户机向每个服务器发送信息，都会有一个新的公网端口，比如你向两个服务器通信，你和第一个服务器通信时给你分配的公网地址和端口是：119.125.123.12:8223，和第二个通信时分配的是 119.125.123.12:8224，只要公网 IP 一样，端口不一样，这就是对称 NAT。</p>
<h3 id="完全锥形-NAT"><a href="#完全锥形-NAT" class="headerlink" title="完全锥形 NAT"></a>完全锥形 NAT</h3><p>这就简单了，就是都能通过给你分配的公网 IP 和端口和你通信。加上限制就是限制锥形 NAT</p>
<h3 id="判断顺序"><a href="#判断顺序" class="headerlink" title="判断顺序"></a>判断顺序</h3><ol>
<li>先判断是不是 完全锥形 NAT</li>
<li>再判断是不是 IP 限制锥形 NAT</li>
</ol>
</div></article><div class="post-copyright"><div class="post-copyright__author"><span class="post-copyright-meta">文章作者: </span><span class="post-copyright-info"><a href="mailto:undefined">wenmu</a></span></div><div class="post-copyright__type"><span class="post-copyright-meta">文章链接: </span><span class="post-copyright-info"><a href="http://blog.wangpengpeng.site/2020/01/09/Peer-to-Peer%E7%AC%94%E8%AE%B0/">http://blog.wangpengpeng.site/2020/01/09/Peer-to-Peer%E7%AC%94%E8%AE%B0/</a></span></div><div class="post-copyright__notice"><span class="post-copyright-meta">版权声明: </span><span class="post-copyright-info">本博客所有文章除特别声明外，均采用 <a href="https://creativecommons.org/licenses/by-nc-sa/4.0/" target="_blank" rel="noopener">CC BY-NC-SA 4.0</a> 许可协议。转载请注明来自 <a href="http://blog.wangpengpeng.site">温木的博客</a>！</span></div></div><div class="post-meta__tag-list"><a class="post-meta__tags" href="/tags/P2P/">P2P</a></div><div class="post-qr-code"><div class="post-qr-code-item"><img class="post-qr-code__img" src="https://i.loli.net/2020/02/27/hOBzIxFDJMCrmtN.jpg"><div class="post-qr-code__desc">微信打赏</div></div></div><nav id="pagination"><div class="prev-post pull-left"><a href="/2020/01/09/Centos7%E5%AE%89%E8%A3%85forever%E5%92%8Cpm2%E5%A4%B1%E8%B4%A5%E8%A7%A3%E5%86%B3%E6%96%B9%E6%B3%95/"><i class="fa fa-chevron-left">  </i><span>Centos7安装forever和pm2失败解决方法</span></a></div><div class="next-post pull-right"><a href="/2020/01/09/JavaScript%E4%B8%AD%E5%8F%98%E9%87%8F%E5%92%8C%E5%87%BD%E6%95%B0%E7%9A%84%E5%A3%B0%E6%98%8E%E6%8F%90%E5%89%8D/"><span>JavaScript中变量和函数的声明提前</span><i class="fa fa-chevron-right"></i></a></div></nav><div id="vcomment"></div><script src="https://cdn1.lncld.net/static/js/3.0.4/av-min.js"></script><script src="https://cdn.jsdelivr.net/npm/valine/dist/Valine.min.js"></script><script>var notify = 'false' == true ? true : false;
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